The work carried out at Fittleworth was primarily focused on creating optimum habitat for coarse fish fry and provides tiny fish with both a suitable location for feeding as well as a refuge during high flow events. Coarse fish fry have very limited swimming ability and rivers where the bed has been lowered through years of maintenance dredging often speed up rapidly during a heavy rainfall event. Peak flow velocity usually occurs before any ​“out of bank” flooding and it is these events where a lack of backwater habitat results in small fish being flushed downstream and over structures with no route back. If these heavy rainfall events occur in the summer, when fry are small and weak, it often results in a huge loss of recruitment to the population.

The backwaters also double up as a safe drinking bay for livestock which reduces trampling pressure on other sections of vulnerable bank.

Shallow, low flow zones are also important for salmonids immediately post gravel emergence but these backwater habitats are usually more attractive to juvenile coarse fish. These habitats also provide a valuable food resource for adult trout and other predatory species and as such are vital in providing habitat to compliment the food chain. Yet another example or the importance of habitat heterogeneity in a healthy ecosystem.